Study on Pore Filling Process and Cluster Evolution Mechanism of Adsorption on Porous Materials
In order to study the adsorption characteristics of materials with different pore sizes and microporous filling process,the pore adsorption during silicon-N2 adsorption was investigated using a combination of experimental and theoretical methods.The thermodynamic analysis of the adsorption isotherms of the nonporous materials was used to obtain the true Zeta adsorption isother-mal constants of the materials,and it was found that the entropy of adsorption in the range of low pressure ratios first increased sharply and then decreased,and then began to increase again after reaching a pole.The molar latent heat is negative in this range,indicating the instability of the adsorbent at this time,from which the unstable interval determines the pressure ratio range of the microporous filling process.The pressure ratio and the corresponding cluster size at the beginning of the pore filling process of mesoporous silica materials were determined using the Zeta isothermal constant of the corresponding system.The cluster molecules were analyzed in relation to the pore size,and the scaling factor decreased with the increase of the pore size,and a physical model was proposed for the earlier merging of clusters at the adsorption sites due to the wall bending of the pores to start the pore filling process.
microporous fillingZeta cluster adsorption modelentropy of adsorptionpore fillingclusters
NETL
NSTL
万方数据
